Discrete-time adaptive control of linear plants with uncertain time delay

A scheme for the adaptive control of discrete-time linear single input single output (SISO) plants with unknown time delay is presented. It does not require the explicit identification of the unknown time delay, and is characterized by a complexity which is comparable to that of the undelayed discrete-time plant. The order of the resulting controller is known and independent of the sampling interval. The underlying linear structure of the proposed control scheme is designed in such a way that only the slow dynamics of the controlled plant is assigned. In spite of this approximation, the overall adaptive control scheme turns out to be globally asymptotically stable